Table stakes

The very first smartphones, such as 1994's IBM Simon, could barely be considered smart. They were glorified personal digital assistants (PDAs) with a cellular modem so you could also make calls. If you could so much as tap a number in your address book app and have it automatically pasted into the phone dialer app, that was considered state-of-the-art.

By 2007, the original iPhone was far more sophisticated, but even it didn't have GPS, 3G data, a hardware keyboard, Palm Pilot-esque stylus, a removable battery or stereo Bluetooth support, many of which were considered table stakes for high-end phones at the time.

In 2017, these are the features you can take for granted in a high-end phone:

Big, beautiful screen: The race for bigger screen sizes is over. Most high-end phones will have a 5-inch screen or larger, while Plus-sized phones range range between 5.5 and 6.3 inches regardless of manufacturer. And unless the company cheaped out, you'll be looking at a crisp display and won't see pixels with a naked eye.

Speedy processor: These days, there's enough power to run practically any app or game on any modern device. Don't pay attention to megahertz, unless you're doing something extreme.

Enough camera megapixels: 12 megapixels are all you need for crisp, detailed photos, and cramming in more of them can actually hurt low-light camera performance. That's why some of our favorite phone cameras -- including those found on the iPhone, Pixel and Galaxy -- stop around 12. More isn't necessarily bad, but it's generally not better.

Metal and glass: For a while there, metal and glass phones were premium, and plastic was still OK. Now, hefty, shiny materials are table stakes for high-end handsets and are even trickling down to inexpensive phones such as the Moto G5 Plus.

Thin is in: The majority of recent phones are as thin as four or five US quarters stacked together. That's between 7mm and 8.75mm, if you don't have those coins handy.

4K and slow-mo video: They're nice to have, but there's nothing special about these capabilities anymore.

Fast Bluetooth, Wi-Fi, and LTE cellular: Some phones do have slightly faster versions of these wireless technologies than others, but only under certain circumstances. This may change as Gigabit LTE and 5G roll out.

Fast charging: Ditto -- some phones and chargers are faster than others, but practically every new, high-end phone can charge faster than the ones that came out a couple of years ago.

State-of-the-art

Are these features are essential for a modern phone? Hard to say, but these are the trends that separate the latest, greatest handsets from everything else.

A camera that "just works": There's no magic bullet here, but the combination of wide apertures, fast autofocus, image stabilization, automatic HDR modes and good software mean that today's top phones can make nearly every picture you take a "good one." It's one of the main things separating high-end phones (such as the iPhone, Samsung Galaxy and Google Pixel) from cheaper handsets.

AMOLED displays: Samsung has a near-monopoly on phone-sized OLED screens. But their vibrant colors, inky blacks, power efficiency and VR compatibility have made these screens a must-have for flagships including the LG V30, Motorola Z2 Force, Z2 Play, Google Pixel, OnePlus 5 and now the iPhone X as well.

Tumble-tough materials: Whether it's the shatterproof screen of a Motorola Z2 Force or the titanium frame and ceramic back of an Essential Phone, some of today's flagships can take a drop better than others. Our Galaxy S8 drop test showed that Corning's Gorilla Glass 5 also does an OK job, and it's the material likely to appear on an increasing number of phones. The new iPhone X also has a stainless steel band that could theoretically resist scratches better than aluminum.

Water resistance: Starting with the Galaxy S7 and iPhone 7, today's slim Samsung and Apple flagships can often survive a dunk in the pool. (Also see: LG G6, HTC U11.) Don't do it on purpose, though, and make sure you're buying a phone rated IP67 or IP68. Anything less, like the Google Pixel's IP53, may not even survive a steamy shower.

Fingerprint scanner: For whatever reason, the fingerprint scanner still isn't ubiquitous on top-tier phones, but it can unlock the ability to easily tap-to-pay at retail stores (and sometimes train and subway stations) around the globe. If a flagship phone -- such as the new iPhone X -- doesn't have it, we ask why.

SD card for expandable storage: SD cards are back and bigger than ever -- so long as we're talking Android phones. The iPhone, and phones that want to be the iPhone, still leave them out.

Easy SIM swap: Unlocked phones will increasingly let you switch between any major carrier just by swapping a SIM. Some phones -- the Google Pixel, Essential Phone, and Moto Z2 Play -- are pretty safe bets. But sometimes you'll need to buy one specific version (iPhone), a phone might be missing a particular carrier (the unlocked HTC U11 doesn't do Sprint), or you'll have to jump through other hoops. Motorola's compatibility checker shows how confusing it can be.

Virtual reality: Stick your phone into a headset for a taste of the future. Any modern Samsung Galaxy phone can plug into a Samsung Gear VR, and there are currently 11 handsets that work with Google's Daydream View.

Differentiators

Only a handful of phones have these features, and it's not always clear why. But their manufacturers use them as selling points.

Wireless (inductive) charging: This feature, where you can drop your phone on a charging pad instead of plugging it in with a cable, was actually on the decline until Apple announced that every new iPhone will support it. You can also find it on every recent Samsung Galaxy (S6, Note 5 and newer).

Iris and facial recognition: Log into your phone with your eyes or face. Standard on Samsung's Galaxy S8 and Note 8, the LG V30 and the new iPhone X, as well as some niche phones in Asia. Just know that not all facial recognition tech is created equal.

Snap-on modular accessories: Only Motorola's Z series and the new Essential Phone currently support modular parts since Google and LG abandoned the idea. So far, they're mostly just niche camera add-ons and beefy battery packs, but the sky's theoretically the limit.

Curved screens: This is mostly Samsung territory, but we've occasionally seen slightly curved screens from other manufacturers too (LG). They look incredible. And depending on the phone, they may aid in multitasking.

Zoom lens: Not all dual-lens cameras are the same. A few -- including the iPhone 7 Plus, iPhone 8 Plus, iPhone X, Galaxy Note 8 and OnePlus 5 -- allow you to crisply zoom in on your subject with their second telephoto lens.

The Note 8 (and iPhone X) have two cameras, one of them a zoom (telephoto) lens, and each with optical stablization.

Samsung

Bloat-free UI: The Google Pixel, Essential Phone and Apple's iPhones are among the precious few phones that don't pile on all sorts of unnecessary third-party software, and we still don't know why more manufacturers don't follow suit.

Hop between different cell networks: If you could always swap to the cellular network with the best signal strength, wouldn't that kill? Unfortunately, you can only use Google's auto-hopping Project Fi cell service with Google's own Pixel or Nexus phones or the Moto X4 -- and dual-SIM phones (which can take two normal SIM cards) are rare, at least in the US.

One foot out the door

These ideas are still hanging on, but they've fallen out of favor. Fair warning: they might be gone for good next year.

Headphone jack: Last year, Google taunted Apple (and Motorola, and others) for removing the 3.5mm audio jack. Now, we're hearing the Pixel 2 might nix it as well. Samsung, LG and others are still holding on, but for how long?

Where we want phones to go next

For all its luster and sparkle, there's not a lot about the iPhone X that truly pushes the phone forward. In many ways, Apple's playing catch-up -- rival phones have had an edge-to-edge design, AMOLED display and wireless charging for months or years now.